The US budget deficits are the annual amount the US government is spending beyond the revenue it's taking in. It's not to be confused with the US national debt owed which is the cumulated amount of annual deficits. The budget deficits under President George Bush reached above 400 billion dollars in 2004 and 2008 and was lowest in 2001, 2002 and in 2007. The economy was strongest in 2007 which increased tax revenue reducing the deficit. In the last two years under Obama's leadership the deficit reached well over one trillion dollars for the first time. Many people have become concerned that the deficits may expand to levels that can't be sustained and that it will lead to either a default or the need to print money to pay the deficits causing high inflation.